CABLE SCREEN FOR FISH PROTECTION PURPOSES
An apparatus for holding back, and diverting, fish in bodies of water by the arrangement of parallel cables braced between two or more abutments, wherein the distance between the cables is small enough to prevent fish from swimming through the apparatus.
Gratings typically are arranged near the inlets to hydroelectric installations. An essential function of these gratings is fish protection. In their capacity as a mechanical barrier, the gratings are intended to prevent the fish from swimming into the turbine inlets in their downstream migration. Depending on the type of turbine and the size of fish, some of the animals entering the turbine area are injured or killed. The smaller the gaps between the bars of the gratings, the better the fish are held back.
The fish protection cable screen offers a fundamentally different construction and mode of operation than state of the art gratings. The mechanical barrier required for fish protection is achieved by a plurality of cables braced parallel or substantially parallel to one another. Typically, the cables are braced horizontally below the surface of the body of water between two or more abutments. In this way, large span widths can be achieved inexpensively and making the best possible use of the material properties. The fish protection cable screen can easily be opened completely by casting off the individual cables. This is particularly important with high outflows to avoid log jams and harmful interactions with the bed load. Also the fish protection cable screen is cleaned by partially or completely laying the cables flat and then stretching them tight.
- Inexpensive and easy to use
- Better fish protection than state of the art solutions
- Highly customizable and easy to construct
- Cleaning of debris (logs) is simple and cheap
StichworteHydraulic engineering, Foundations, Underwater structures, Care of fishes